Rotary electromagnetic actuator



Feb. 8, 1966 J. J. BIEGER ROTARY ELECTROMAGNETIC ACTUATOR Mm QNQQN Q Q Qg Filed Sept. 12, 1962 Feb. 8, 1966 J. J. BIEGER 3,234,436

ROTARY ELECTROMAGNETIC ACTUATOR Filed Sept. 12, 1962 2 Sheets-Sheet ZINVENTOR. Jacoa ul' 3/5657? aymWw ATTORNEYS United States Patent-3,23%;436 RQTARY ELECTROMAGNETIC ACTUATOR"- JaeobfL Bi'eger,"Queen'srVillhggwNzYa; assignorpby; mesne assignmentst-r tow-"DacoiInstrument Company; Inca, Brooklyn NzYt-qpa corporationmf New York-Filedasept 12 1962,: Ser.. No, 223,164

7 Claims. (Cl'.f317---197) This invention relates to rotaryelectromagnetic actu atoi'sf More particularlyfi this invention relatesto sole noids having rotatable armatiifes which may be angularlydisplaced "to one of three"distinctpositions.

The typvof solenoid? to: which the *pres'entinventio'n pertainshasparticularutilityas an indicatingdevice' in electricalcircuits. Itisoftennecessary to give-a visual indi'c'ation to "showwhich'of aplurality of circuits has been energized? As "a specific example; itmight bedesirable" to'indicate whichod two' circuits *is in anenergizedstate 'orgwhe'ther neither hasbeenenergized; For purp'oses'of simplicityand economy, such a visual -indication maybe readily given by. placingthe coils oi'a rotary elec tro'rnagnetic actuator, or. solnoidfin theseparate circuits whereby a visual indicator may be -rotated' in one of-two directions depending on which circuit is energized. If theindicator remains in its initial position this would 'mean that neithercircuithas "been energized; Accortiirigly,' it is-an objctbf'this-invention to provide an improved three-position rotary solenoidsAnother object is to-provide a rotary solenoid which i's rugged'indesign, simple in construction and economical to manufacturer.

The'objects of'tthe invention areraccom-plished by providing twooppositely disposed stator sections,-a rotor shaft extendingtherethrough', t and a pain of rotors rotatably displaced fromone.another and associated with respective stators, the rotorsbeingaindividually. operable to rotate thev shaft in a given directionwhen the coil of its=associated-statoris energized. A return means,which may comprise a pair ofpermanent magnetsioperative in conjunctionwith thefouter pole pieces ofthe'stators, biases the rotor shaft-to itscenter position; so that whenneither coil is energized the shaft willmaintain its initial 'position.

The mannerin which these objects are 1 accomplished will i b'e furthetexplained -with reference to "the following specification anddrawingsywher'ein t FIG-1- lis an exploded view ofrtheithree-positionactu, ator accordingntoi the: invention;

FIGJ 2 is'ia side view in section of the rotary actuator;

FIG 4 is aview'alongztheline le4 of FIG. 2; t FIG. Sis 'a-crossrsectional view-tof another embodiment of thetinvention;

FIG; 6-is -a cut-iawayttopsview of the embodiment of FIG 4; and

FIG. 7 is an exploded view of the rotor and jstoprmember of the secondembodiment.

In FIGS. .1-to:3,1the' three-positionrotary solenoid is shown comprisingfirst-and second statortsections 10 and 12, respectively.Statorsection'10includes a base 14, a cylindricalwall'-15press--fitthereover; and an' outwardly extending center'pole piece 16*ii'1tegrallyformedwith base 14 lnadd-itiong stator-section '10 in'clu'des twooppositely disposed, outer pole/piecetrnembers lhand 18 integrallyformed with wall 15. Stator section 12.. is constructed identically asstator 10'and includes .a' base 20,?a center pole piece 21, and .twoouter pole pieces 22 and23extendingfrom ta;cylindrical wallpor-tiont24.The stators are made of a material which will provide suitable fluxpathswhen -the solenoid is energized; i As shown-in FIG. 2, the statorsof the assembled solenoid are arranged in end-to-end relationship withbase 14 abutting against base 3,234,436 Patented Feb. 8, 1966 20; andpole pieces' 17 and ls' of stator- 10*alignted with pole pieces 22 and2'3, respectively; of stator 12? The stators may 'be 'held 'in thisrelationship by-ineans is Wound-around *a' second spool -lik'e coil form-34 hav ing a central-bore"35 "into whichcenter polepiece 21 extends.--

The center pole pie'ces are "slightly longer than their associated coilform'; so thatwheiithe "ends -of coi'l forms 30 and =32-rest against thetops spectively; the upper portions o protrude from the coil for msi Arotor shaft "38 extends through the center-' of c'oil forms 30- and 32and is "suitablyjournaled in bearings 33 in center pole pieces 16 and-21- of "statorsect-ions= 10 and 12, respectively. A first bow-shaped"rotor 40='includingan integrally formed hub me'mber' '42" is-secured toshaft 38 immediately above centerpole *piece' -16i Rotor 40 rnay -bemadeof: solid magnetic material and includes a centerrecess 43 beneath hub42'i into which the protruding end' of center-pole piece 16'extends. Ina similar manner, a second -bow-shaped rotor 46' i'nclud ing an--integralhub -member 47 f issecured 'to sha ft 38 opposite rotor 40.Rotor: 46 is also centrally recessed; so that the protruding end ofcenter-pole piece 21iextends substantially into the :rotorr When! one ofcoils 28 and 32 is energized;=a magnetic flux is generated iinrits?associated stator wall andipole pieces. Th'e respectiver'rotorrisattracted -by theimagneticlines of flux:"passingrtransversely throughtthe air gap (betweenrthe' rotor'and 'outer' pole pieces) tothe rotorr.Theesalient'epoles of the "r'otortare attracted to the stator polepiecessoft opposite'ipolarity thus imparting a'rotary motiodtoitherotor; By'utilizing recessedrotors and' mounting the mover respectivecenter pole pieces of teach. stator, theetfectof :the magneticthrustwhich acts downwardly: on'vthetrotors, and thus-Lterids to lessen thetorque developed during rotationfis minimized. As *shown in 'FIGS'. 3and -4,' the'rotors are' rotatably -dis placedon shaft 38' with: respectto each'cothertso that energizationof coili28 x-will 'cause' "rotor 40'to. rotate shaft 38 r'in'iazclockwise direction,'rwhi'le energization'iof coil-32 will cause rotor 46 rtot rotaterthe 'shaftt'in acounter-clock;

wise direction;

Rotor shaft 382 is: returned?! to its initial-* position by means :of a.pairofflat; annulartpermanent magnets. 48 and 50 which maybe-'pressxfit ito hubmembers 42and 4-7", respectively; Magnets48 Sand 50fliHVG magnetic :fields 'as illustrated :in FIGS.- 31 and-:+4;whichgexertiforcesrwith respect to their associated outer pole pieceswsothat magnet' 48" tends s to rotatei shaft- 38 counterclockwise, whilemagnet SU-vtends to rotatev'theshaft in: a? clockwise direction-.1Accordi'nglygxwhenathe solenoidis-deaenergized; the rotor. shaftmaintains a position in :whichthe opposing magnetic forcesaret equal or'balanced. I

The solenoidalso *includcswa; pair: ofrthin'a'nnular stop members 52and- 54 press fitted': to' the" extremities of. hubs Y 42 and 1:47,"respectively;v for limiting "the rotary movement'ofishaft38.Stopirme'mber SZ includes cars 55 and 56adapted to abutagain'st-ou-terp'ole pieces -18 and 17, respectively; whenishaft38 isrotatedfclockwiser Stop member 54* includes ears 57" and r 58?" adaptedto: abut against pole pieces 22 and 23,..respectivel-y; when-shaft 38is-rotated in a counterclockwise;direction-.=

The/entire solenoid may becenclosed in a pair iof:cylin'- drical endcaps 60 and 62. A small insulated tubex64 fits into aperture 65 of tube60 to receive the leads of wise direction until the movement is arrestedby abutment of the ears of stop member 52 against outer pole pieces 17and 18. When the energization of coil 28 is removed, the unbalancedforces of the displaced magnets 48 and 50 return rotor shaft 38 to itsoriginal position at which point the :forces -of the two magnets areagain balanced; Similarly, if current is passed through coil 32, rotor46 rotates shaft 38 in a counterclockwise direction, and when thecurrent is removed, the unbalanced magnetic fields of magnets 48 and 50return the shaft to its initial position. An alternate embodiment of theinvention, in which a return spring is employed, is illustrated in FIGS.-7. Only one stator section is illustrated, since the second sectioncould be substantially identical, as discussed above with reference toFIGS. 1-4. In fact, since the individual stator sections would haveutility by themselves in any situation wherein only two separate angularpositions are necessary, this embodiment will be described as a singlestator, two position, rotary solenoid.

The stator of the second embodiment includes a base 72 and a cylindricalwall 70 press fit thereover. A pair of integral, curved pole pieces 74and 76 extend upwardly from wall 70 at opposite ends of a diameter. Acenter pole piece 78 is integrally formed with base 72 and includes asuitable bore for receiving a rotor shaft 82. A rotor 80 including hubmember 81 (as shown in FIG. 7), is fixed to shaft 82 near the topthereof.

A spiral return spring 84 is wound around rotor-hub 81 immediately aboverotor 80. One end of spring 84 is secured to hub member 81 while theother end is secured to pole piece. 76 through a slot 86 in the polepiece. Spring 84 exerts a force which tends to rotate rotor 80 in aclockwise direction.

A stop member, comprising a circular disc 88, is secured to the top ofhub 81 immediately above spring 84. Disc 88includes a pair of oppositelydisposed ears 89 and 90 adapted to abut against edges 92 and 93 of polepieces 74 and 76. The stopmember and rotor are slightly offset from oneanother so that when coil 79 is energized and the rotor is rotatedcounterclockwise from the deene'rgized 3. A rotary electromagneticactuator comprising, a first stator having a first coil and a firstrotor associated therewith, a second stator having a second coil and asecond rotor associated therewith, said firs-t and second stators eachincluding a central pole piece and a pair of oppositely disposed polepieces, each of said central pole pieces extending into and beingperpendicular to its respective rotor, a rotor shaft passing throughsaid stators, said first and second rotors'bcing secured to said shaftand disposed relative to their respective pole pieces wherebyenergization of said first coil causes said first rotor to rotate saidshaft to a first position, and energization of said second coil causessaid second rotor to rotate said position indicated in FIG. 6, the cars89 and 90 abut against edges 93 ofipole pieces 74 and 76. Whenexcitation is removed, spring 84 rotatesithe rotor clockwise to itsinitial position as determined by abutment of cars 89 and 90against'edges92 of the outer pole'pieces.

Although specific embodiments of the invention have been disclosed,manymodifications thereof will be obvious to one skilled in .the art andthe invention is not to be limited except as defined in the followingclaims.

I claim:

1. A rotary electromagnetic actuator comprising a first 'coil and firstpole pieces associated therewith, a second coil and second pole piecesassociated therewith, a rotor :shaft passing through said coils, firstandsecond rotors secured to said shaft and operativelyassociated withsaid first pole pieces and said second pole pieces, respectively, :saidrotors being disposed relative to their respective pole pieces wherebyenergization of said first coil causessaid first rotor to rotate saidshaft to a first position and energization of saidsecond coil causessaid second rotor to rotate said shaft to a second position, and a meansbiasing said shaft to a third position intermediate, said first andsecond positions.

2. A rotary electromagnetic actuator as recited inclaim -1 wherein saidbiasing means include. a permanent magnet.

shaft to a second position, stop means for limiting the rotation of saidshaft in either direction, and means for returning said shaft to aninitial position intermediate to said first and second positions whenneither of said coils is energized. i i

4. A rotary electromagnetic actuator according to claim 3 wherein saidreturn means includes magnetic discs secured to said rotor shaft andoperatively associated with said first and second stators, the magneticforces of said discs being directed so as to bias said rotor shafttosaid initial position. I

5. A rotary electromagnetic actuator according to claim 4 wherein saidfirst and second stators are identical and include a cylindrical baseintegrally formed with its respective pole pieces, said stators beingarranged in endto-end fashion, one of said rotors being displaced in acounterclockwisedirection with respect to its pole pieces, and the otherrotor being displaced in a clockwise direction with respect to its polepieces.

6. A rotary electromagnetic actuator according to claim 5 wherein saidstop means includes a membersecured to said shaft and adapted to abutagainst the pole pieces of one of said stators.

7. A rotary electromagnetic actuator comprising a cylindrical statorhaving three elongated pole pieces arranged in spaced locations, two ofsaid pole pieces com prising opposing portions of the cylindricalsurface of said stator, the other pole'piece extending axially from thecenter of said stator, a rotor shaft rotatably' mounted in said centralpole piece,- extending. through the central pole piece of said stator,and beyond the opposing pole pieces, a rotor secured to said shaftadjacent the free end of said central pole piece, said central polepiece extending into and being perpendicular to said rotor, said rotorhaving outer faces arranged to rotate past the inside faces of saidopposing pole pieces, electromagnetic means sure rounding'said centralpole for energizing said pole pieces to rotate said rotor in onedirection, spring return means to rotate the rotor in the oppositedirection when said electromagnetic means is not effective and,stop'means for limiting the rotation of the rotor, said stop meansincluding a segmented disc-like member secured to said rotor havingmeans to abut against one of said opposed pole pieces.

References Cited by the Examiner UNITED STATES PATENTS i Y 2,869,0481/1959 Reed; 317491 2,950,424 8/1960 Smith et al. 317 6 5-X 3,039,0276/1962 Cuches 317 1 97 V FOREIGN PATENTS 830,225 2/1952 Germany. I

102,130 8/1962 Holland.

BERNARD GILHEANY, Primary Examiner. 7 JOHN F. BURNS, LARAMIE E. ASKIN,Examiners

1. A ROTARY ELECTROMAGNETIC ACTUATOR COMPRISING A FIRST COIL AND FIRSTPOLE PIECES ASSOCIATED THEREWITH, A SECOND COIL AND SECOND POLE PIECESASSOCIATED THEREWITH, A ROTOR SHAFT PASSING THROUGH SAID COILS, FIRSTAND SECOND ROTORS SECURED TO SAID SHAFT AND OPERATIVELY ASSOCIATED WITHSAID FIRST POLE PIECES AND SAID SECOND POLE PIECES, RESPECTIVELY, SAIDROTORS BEING DISPOSED RELATIVE TO THEIR RESPECTIVE POLE PIECES WHEREBYENERGIZATION OF SAID FIRST COIL CAUSES SAID